The present invention relates to a throttle opening control device for a marine propulsion arrangement, and more particularly to a device which may be utilized in connection with the propulsion arrangement of an outboard motor, wherein the angle of throttle opening may be regulated, and automatically controlled, by an interconnection to the transmission shifting system.
The induction systems for many internal combustion engines frequently employ throttle valves. Throttle valves control the air flow through the induction passages of respective charge forming devices. The position of the throttle valves, and thus the amount of air inducted, may be controlled by an operator by way of a remote shift-type lever or a remote rotatable hand grip, for example, as upon the tiller of an outboard motor.
It has been known to interrelate the operation of such a throttle control arrangement with the operation of a transmission system, having forward, neutral, and reverse operating stages, in order to avoid certain problems. Problems might be incurred, for example, when attempting to start, or restart, an engine when the throttle is set for a high engine speed, or during an attempt to urgently shift the transmission into another operating stage during engine running conditions. The consequences of such problems might include quick and jerking water vehicle motions, tending to throw passengers off balance, or breakage of the shift control mechanism.
In certain prior types of marine propulsion devices, the transmission may be shifted from forward to neutral, or from reverse to neutral, only when the throttle opening angle is within prescribed safety limits. Also, the engine may be started only when the transmission is in the neutral stage. By employing such arrangements, the above-mentioned potential problems can be avoided.
The above-discussed prior art devices have, however, been recognized as lacking in operational efficiency in certain respects. For example, when operating an engine above idle speeds, before it is fully warmed up, stalling may occur. In accordance with the prior art devices, a two-step procedure must be carried out in order to restart the engine. First, the throttle must oftentimes be adjusted so that its opening angle falls within the prescribed safety limit, as it will likely have been moved outside such limit during operation. Next, the transmission must be shifted from the forward or reverse operating stage to the neutral operating stage. It is only at this point, then, that restarting may be initiated. Similarly, during usual running conditions in order to shift between the various transmission operating stages it is usually necessary, first, to decrease the throttle opening and, then, to make the desired shift. Thus, it is apparent that restarting, as well as shifting operations, can be a cumbersome procedure.
It is, therefore, a principle object of the present invention to provide an improved throttle opening control device for a marine propulsion arrangement.
It is a further object of this invention to provide a device which allows an operator of a marine propulsion unit to shift from a forward or reverse operating state into neutral, in order to start or restart an engine, or to effect an urgent transmission shift change during operation, without having to execute an independent step of separately reducing the throttle opening angle beforehand.
It is still a further object of this invention to provide a throttle opening control arrangement wherein the angle of throttle opening is automatically controlled by an interconnection to the transmission shifting system.